Power Adaptor




Introduction: Power Adaptor

I use an old computer power supply to make a lab power adaptor. This power adaptor have fixed and variable voltage. A 5 Volt fix voltage and optional 3.3, 12 and -5 volt with high current outputs and short circuit protection.

Part list:

  • Crocodile clips
  • Binding posts (terminals)
  • Galvanised plate
  • Conectors
  • Wire connector
  • LED
  • 1K resistor
  • Switch
  • Spongebob assistant (optional)

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Step 1: Panel

make your favorite panel, I use galvanised plate and yellow paper. Design and draw panel with computer software and print on paper and paste on galvanised plate. Then drill holes for terminal, LED and switch.

Step 2: Binding Posts

  • Screw the binding posts into their corresponding holes
  • Attach the nut on the back as shown on pictures

Step 3: Switch and LED

Mount switch and LED on the panel.

Use 1K ohm resistor and solder to LED and notice the polarities.

Connect and solder black and green wire to the switch

Step 4: Power Supply

  • Open up the power supply unit
  • Seperate red, orange, green, white, yellow and 3 black wire
  • Cut other wires
  • Make sure wire not connected together

Wire Colors:

  • Red: 5V
  • Yellow: 12V
  • Orange: 3.3V
  • White: -5V
  • Green: Power on
  • Black: GND

The color of wires may be different, see this link or use a voltmeter.


Step 5: Connecting Wires

Solder orange, yellow, black and white wire and connect to binding posts as shown

Step 6: Crocodile Clips

  • Use Crocodile clips for fixed 5v
  • Connect crocodile wires to red and black
  • Use wire tape

Step 7: Hot Glue

Use hot glue to fix LED, switch and wire

Step 8: Wire for Others Voltage

This link is a greatEncyclopedia of ATX to Bench Power Supply Conversion, thanks to russ_hensel


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    11 Discussions


    4 years ago

    what wires connect to the led and how?


    Reply 4 years ago

    Like this:


    Reply 4 years ago

    Thanks. I was kinda confused bc I saw a brown wire in one of your pictures connected to the LED and was thinking where it came from.


    4 years ago on Introduction

    LOL the spongebob assistant is very funny. Nice that you have some humor in your instructable.


    Reply 4 years ago on Introduction

    thanks for attention

    it is great and useful

    I add to my post